History of water supply in Tehran

Contrary to most cities, Tehran is not build near rivers and
the required water has to be supplied from nearby areas and bodies of water.

Until 1927,
the water supply of Tehran was provided through 26 Qanats with a watering of
700 liters per second. In 1927, the operation for establishment of a water
canal to transmit the water of Karaj River to Tehran was initiated. The canal
was 53 km long transmitting water from the village of Bileqan in Karaj to
Jamshidabad in Tehran and was constructed in 4 years. 20 km of this canal was
covered and there was a possibility of contamination and water loss. Through
this canal, 53 “stones” as right of water and nine eighty-fourth as quotas was
added to Tehran’s water supply, which made the total amount of water
distributed throughout the city to be 100 “stones” (1600 liters per second).

In 1950, the first plan for pipeline was carried out for 900
people and two steel pipelines with a diameter of 40 inches and a capacity of
242000 cubic meters a day were considered to transmit water from Bileqan intake
to Tehran’s first water treatment plant called Jalaliyeh. The first pipeline
and Jalaliyeh treatment plant were launched in 1955.

In 1954, in order to control rainfalls, studies were
undertaken to construct Amirkabir Dam located 40 km in northwest of Tehran
(from Kharsangkooh pond) near Varyan Village in Karaj-Chalus road.Construction of the dam was started in 1958
and finished in 1963.

In order to meet the ever-increasing demand for water in
Tehran, the second water treatment plant called Kan and two concrete mains with
a diameter of 2000mm were established to transmit water from Bileqan intake.
This construction was operated in 1964.

The increasing trend of migration to Tehran and
overpopulation created new demands and this caused the authorities to seek
solutions for increasing the capacity of water supply and development of
facilities. Hence, underground waters were considered for usage to meet the
needs of citizens along qanats and Karaj Dam, especially during peak moments of
water use during summer. Digging deep wells was started in 1963 and their
numbers increased ever since.

In 1961, studies for construction of Latyan Dam, located 32
km to the northeast of Tehran was started to control the water of Jajrud River.
In the construction plan, water supply to parts of Tehran and Farmlands of
Varamin plain had been considered. This dam was operated in 1967, with a tunnel
called Taloo (9km long and a diameter of 7.2m) transmitting water to the
eastern parts of Tehran. Tehran’s third water treatment plant was started at
around the same time in Hakimiye, which was operated in 1968. The plan for the
development of this third water treatment plant and establishment of a fourth
one was finalized in 1984.

Following more requirements, studies for construction of an
earth dam on Lar River in the northeast of Tehran in Kalan Mountains in an area
called Polur on Haraz road (Tehran-Amol) was carried out. The dam was completed
in 1981 and operated in 1984.

One of the objectives of construction of Lar Dam was to
increase the water supply of Tehran, but because of water runway, it was not
possible to use the nominal capacity of the dam. The stored water is transmited
via Kalan tunnel (20 km long with a diameter of 3 m) up to 3 km from the lake
of Latyan Dam and after supplying two power plants of Kalan and Lavarak enters
the lake.

The overgrowth of Tehran has created a situation in which the
water resources in dams of Karaj, Latyan and Lar and deep wells, that were
supposed to be used as last resources during times of increased consumption,
are no longer enough to provide for the population of this city. As a result,
underground water beds were used in an increasing trend. The limit of usage
from these underground sourses has been determined to be 250 million cubic
meters a year.

Planned withdrawal of underground sourses of Tehran
(including several small water tables in the north in Nyavaran, Maqsoodbeyg
Valley and Mahmoodye and a large water bed in Abbasabad to the South) started
from 1963. The proportion of underground water to the whole amount of water
provided for the city has increased from 13.5% in 1963 up to 49% in recent years.

Karaj dam has a capacity of 205 Million cubic meters. In 1963
about 56 million cubic meters of water needed for Tehran was provided from
Amirkabir Dam. In 1994 about 339 million cubic meters of water was provided
from this dam and this amount reached to 330 million in 2002.

In the start of using Latyan Dam in 1968, about 3.13 million
cubic meters of water requirement of Tehran was provided from this dam and this
amount increased to 165 million a year in 1984. With the operation of La Dam in 1984, each year some water is
transmitted from there to Latyan Dam.